a = 1+1
print a
If you already knows python, you know how to integrate it to a ROS environment. It is also possible to do it in here, take a look below:
import rospy
print 'Hello from IPython to ROS'
print rospy.get_param('/rosdistro')
print rospy.get_param('/rosversion')
If you double-click here, you will be able to edit this cell. To get out of the editor mode, press Ctrl+Enter.
Explore the top bar to use all its functionalities.
More about IPython notebooks: https://ipython.org/ipython-doc/3/interactive/tutorial.html
To avoid losing your notebook changes save first the notebook with its saving icon
and then click the general saving icon
at the bottom to save all your project to the cloud.